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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2024-08-22 10:13:13 +0300 |
|---|---|---|
| committer | Jason A. Donenfeld <Jason@zx2c4.com> | 2024-09-13 18:28:35 +0300 |
| commit | b7bad082e113640fc81200ff869e5c2d7a9c29a2 (patch) | |
| tree | d1e95815144303fae74ac0852a20209103730c02 /lib | |
| parent | 81723e3ac388271cf1fe9d9ca8f4e9c74689ea0e (diff) | |
| download | linux-b7bad082e113640fc81200ff869e5c2d7a9c29a2.tar.xz | |
random: vDSO: avoid call to out of line memset()
With the current implementation, __cvdso_getrandom_data() calls
memset() on certain architectures, which is unexpected in the VDSO.
Rather than providing a memset(), simply rewrite opaque data
initialization to avoid memset().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/vdso/getrandom.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c index bacf19dbb6a1..1281fa3546c2 100644 --- a/lib/vdso/getrandom.c +++ b/lib/vdso/getrandom.c @@ -3,6 +3,7 @@ * Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */ +#include <linux/array_size.h> #include <linux/cache.h> #include <linux/kernel.h> #include <linux/time64.h> @@ -73,11 +74,12 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_ u32 counter[2] = { 0 }; if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) { - *(struct vgetrandom_opaque_params *)opaque_state = (struct vgetrandom_opaque_params) { - .size_of_opaque_state = sizeof(*state), - .mmap_prot = PROT_READ | PROT_WRITE, - .mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS - }; + struct vgetrandom_opaque_params *params = opaque_state; + params->size_of_opaque_state = sizeof(*state); + params->mmap_prot = PROT_READ | PROT_WRITE; + params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS; + for (size_t i = 0; i < ARRAY_SIZE(params->reserved); ++i) + params->reserved[i] = 0; return 0; } |